Improper Certificate Validation in RabbitMQ Java Client Library - CVE-2026-63336
Published: July 9, 2026 / Updated: August 19, 2026
Vulnerability identifier: #VU137272
CSH Severity: Medium
CVSS v4: 9.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63336
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to intercept and modify transmitted data.
The vulnerability exists due to improper certificate validation in ConnectionFactory.useSslProtocol() and TrustEverythingTrustManager when establishing TLS connections without explicit trust configuration. A remote attacker can present a crafted certificate to perform a man-in-the-middle attack to intercept and modify transmitted data.
Hostname verification is disabled by default, which further facilitates exploitation.
Affected software
RabbitMQ Java Client Library
How to mitigate CVE-2026-63336
Install security update from vendor's website.
RabbitMQ Java Client Library - update to 5.33.0